| 摘要 |
PURPOSE:To enhance uniformity in a light emitting part without forming the segment of a hologram to have a narrow pitch, as to a display device using the hologram. CONSTITUTION:Light emitted from a light source 1 enters one end of a light guide 3, then, the light is diffracted by a 1st hologram 4 and goes forward inside the light guide while repeatedly reflecting on both inside surfaces of the light guide. A 2nd hologram 5 and a 3rd hologram 6 constituted of many segments are installed on the other end of the light guide so that they may lie on top of the other. Some of a luminous flux P is made incident on the 2nd hologram 5 and diffracted, and then, emitted outside the light guide by a prescribed spreading angle. Besides, remaining luminous flux not diffracted by the 2nd hologram 5 is made incident on the 3rd hologram 6, and then, diffracted and emitted. Thus, the segments of the light emitting part are observed from the outside as if they were doubled, so that the concentration is increased and uniformized and the display having high appealability can be obtained. |
